Joel garfield



JOEL GARFIELD, OF GROTON, MASSACHUSETTS.

' Laim Patent No. 82,935, am carota .13, lacs.

IMPROVE!) RATCHETAND-PAWL The Schedule' referred to in these Letters Patent and making part of the same.

To all'whomfit may concer-nf:

Beit known that I, JOEL GARFIELD, of Groton, in the county of Middlesex, and State of Massachusetts, have invented an Improved -Ratchet-and-Pawl Mechanism; and I do hereby declare that the follow ing, taken in connection with the drawings which accompany and form part of this specification, is a description of my invention sufficient to enable those skilled in the art to practise it.

My improvement relates to the arrangement of a ratchet-driving pawl, with reference to provision for throwing such pawl out of engagement with the ratchet-teeth at will, so that the pawl may be rotated without imparting movement to the ratchet, or m'ce versa, and also so that, in back movement of the pawl, its point shall be drawn in, so as to rotate in a circle'within the circle of ratchetfteeth or without contact with said teeth; and the invention consists in combining with the ratchetewheel and pawl a collar, so constructed and arranged that by movement inY one direction the pawl is lthrown into engagement with the ratchet, and out of, engagement therewith by opposite movement, and also in provision, in connection with such combination, for fixing the pawl out of engagement with the ratchet-teeth.

The drawings represent a ratchet-wheel and pawlmechanism, embodying my invention.

A shows the interior of the pawl-and-ratchet case, the outer or pawl-plate being so broken away as to clearly show the arrangement of the parts, the pawl being in engagement with the ratchet-teeth.

B is a similar view, with the parts so adjusted as to prevent the engagement of the pawl and ratchet-teeth in either direction of rotation of the pawl.

C is a cross-section on the line x x. y

a denotes the ratchet-wheel, the teeth b of which are on the inner surface of the iiange, making an internal ratchet.

c denotes the impelling-pawl hung upon an arm, d, projecting from a boss, e, xed to or forming part of the rotary cap or pawl-plate f, as seen inthe drawings, this pawl-plate `being lmounted and turning on the shaft g which carries the ratchet-wheel a.4 On this shaft g, within theratchetecase or cylinder, is a loose disk or collar, h, near the perimeter of which is a slot, i, into which a pin, lc, projects nom the pawl c, said slot being inclined so that, by turning the collar in one direction,I the pin is forced outwardly, pressing the impelling-face of the pawl up into the ratchet-teeth, as seen at A, while by turning the collar in the opposite direction the pin is forced inwardly, carrying the end of the pawl into the position 'seen at B, in which position the pawl will rotate without engaging with the ratchet-teeth.

On the opposite side of the shaft the collar carries a stud or projection, l, as seen at A and B.

Through the pawl-plate f, I make a slot, m, through which slot passes the shank of a screw, n, having a thumb-nut, o, on its outer or screw-threaded end, and on its inner end or head p, which head, when the screw-shank is moved up to the inner end of the slot m, (as seen at A,) will rotatein a path within the stud l, or without striking said stud, while, when the screwshank is moved to the other end of the slot, (as seen at B,) said head in its rotation strikes the stud'l, and rotates the collar It with it, as will be readily understood.

Now, when the head p and the stud l are thus in contact as seen at B, and the pawl-plate is rotating in the direction denoted by the arrow, (the pawl-pin k being at the ilmer end of slot 73,) the pawl and collar will rotate together, the rotation of the collar being caused by contact of the stud l with the head p,

Vand no relative rotative movement can take place between the pawl-plate and the collar. Consequently the pawl-pin It will be kept at the bottom of its slot, and the pawl. will be kept from engagement with the ratchet-teeth, while, if the pawl-plate rotates in the opposite direction, the inclination` of the slot itselfwill.

hold the pawl away from the ratchet-teeth, the pawl being'uzidcr all circumstances thus held out of contact with the ratchet-teeth by the incline in back movement of the' pawl-plate. If the screw-shank be pushed to the inner end of its slot, as seen at A, and the ratchet-plate rotates as denoted by the arrowat A, the head p will pass inside of the stud l without touching it, and the rotation of the pawl-plate rela--V tively to the collar will cause the pin k to run up the incline i, thereby forcing thepawl up into engagement with the ratchet-teeth, as seen at A.

It will thus be seen that the use of a spring to hold-'.

the pawl against the ratchet-teeth is dispensed with; that the pawl must always and positively be carried into engagement with the teeth in the forward rotative movement of the pawl, (when the parts are adjusted for such engagement that the pawl will always be drawn out of engagement when the pawl is moving in the opposite direction, and that by simple adjustment of the screw-pin n the pawl may be disengaged from the ratchet-wheel. whenever it is desirable for the pawl to rotate without effecting corresponding movement of the ratchet. All wear upon the pawl by its slipping over the ratchet-teeth is thus prevented, as well as the clatter resulting from such slipping movement. There is no spring to break, as in other ratchet-and-pawl mechanisms, and the arrangement is simple, reliable,

' and inexpensive.

I claim, in combination with a ratchet-wheel and pawl arranged substantially as shown and described, the loose collar or disk h, having an inclined slot, intoV which the pawl-pin projects rotation of the pawlplate in one direction forcing the pawl up into engagement with the ratchet-teeth, and its rotation in the opposite direction carrying it out of engagement there with, substantially as set forth.

I also claim, in combination with the ratchet-wheel and pawl and the loose collar, r.the stud l, and adj ustable screw or pin a, operating substantially shown and described.

JOEL GARFIELD. lVitnesses:

J B. CROSBY, FRANCIS GoULD. 

